Electric switch



Nov. 10, 1925.

I G. A. BURNHAM ELECTRIC SWITCH 2 Shuts-Shut 1 Filed Aug. 18, 1920 ,1?! wen 2 07".

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Patented Nov. 10, 1925.

UNITED STATES PATENT OFFICE.

GEORGE A. BURNHAM, OF SAUGI IS, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO CONDIT ELECTRICAL MANUFACTURING COMPANY, A CORPORATION OF MASSACHUSETTS.

ELECTRIC swrrcn.

Application filed August 18, 1920. Serial No. 404,412.

To all whom it may concern:

Be it known that I, GEORGE A. BURNHAM, a citizen of the United States, residing at Saugus, in the county of Essex and State of Massachusetts, have invented an Improvement in Electric Switches, of which the following is a specification.

This invention relates to electric switches especially adapted for the control of electric circuits of comparatively high voltage and current carrying capacity.

Electric switches of the type with which this invention is concerned, because of their oil throwing propensities and the consequent danger from fires by reason of the high voltage, are usually isolated from other switches and-other station apparatus by being enclosed in cells which are usually made of cement; and the switch of one phase is usually isolated from the switches of the other phases of the circuit.

An object of my invention is to provide a switch structure so arranged that no, or but a relatively slight amount of, oil will be thrown out of it because of circuit interruption; and in which the danger of a discharge of flame is minimized, whereby, from the standpoint of fire hazard, it will not be necessary to isolate the switch in a. cell.

A further object of the invention is to provide a. switch structure having means to absorb dynamic energy developed within the switch upon circuit interruption, whereby to increase the current rupturing capacity of the switch.

Specifically, these objects are accomplished by providing a resiliently supported oil receptacle and an enclosing 5 ill receppletely encloses the oil receptacle and which is adapted to catch and retain oil expelled from the oil receptacle.

It frequently happens, that upon a severe overload, the circuit-interrupting arc comes in contact with and burns a hole through the walls of the on receptacle and oil escapes into the station. The hot oil in contact with the arc and air may be set on fire with the result that the fire, may spread over the station. The switch also is rendered inoperative due to loss of oil. With a switch constructed in accordance with rupt current is enhanced.

tacle in the form of a casing w ich commy invention, the oil will flow through the opening into the outer receptacle and be there retained, and will not escape from the switch. While the oil level in the inner oil receptacle may be lowered the switch may yet be in condition for furtheroperation.

A further object of the invention is removably to support the inner or oil receptacle from the switch frame, and to support the outer receptacle from a separate support, as the floor.

Another object of the invention is to provide a. switch of the type described with a comparatively large expansion chamber whereby the ability of the switch to inter- A further object is generally to improve the construction and operation of an electric switch of the type set forth.

Certain features herein set forth are described and claimed in my co-pending applications Serial Nos. 309,853, filed July 10, 1919; 374,276, April 16, 1920; 381,466, May 14, 1920; 386,347, June 3, 1920; 388,324, June 11, 1920; 390,850, June 22, 1920.

Fig. l is a side elevation of an electric switch embodying my invention.

Fig. 2 is a transversesectional elevation along line 2-2 of Fig. 1.

Fig. 3 is a longitudinal sectional elevation along line 33 of Fig. 2.

Fig. 4 is a. Ian view of the switch with the cover and stationary switch members removed.

Fig. 5 is a plan view of the cover with the stationary switch members.

Fig. 6 is a plan view'along line-66 of Fig. 1.

Figs. 7 and 8 are transverse sectional and side elevation views in detail of a modified method of resiliently supporting the oil receptacle.

Fig. 9 is a vertical sectional detail of a further modified method of resiliently supporting the oil receptacle.

As here shown the switch embodying my invention is enclosed within the casin including the top frame structure 10 an the lower frame structure 11.

The top frame structure has the relatively deep side walls 12 whereby to rovide a relatively large expansion cham r 12 above the oil in the oil receptacle disposed within the casing. flanges 14 extend peripherally about the side walls and deep. ribs 15 tie in the walls and flanges whereby to form a strong casing well adapted to resist relatively great internal.

tacle; and a peripheral flange 19 extends up wardly from the edge of the well to guide and support the bottom portion of the oil re-' ceptacle.

Rods 20. or equivalent are threaded into the lower flange 14 of the upper frame structure 10 beyond the apron. 17 and extend downwardly through openings in the lower frame structure 11. Nuts 21 threaded on the lower threaded ends of said rods secure said rods firmly to the lower frame structure; whereby the top and bottom frame structures are'firmly united in a rigid unitar structure.

bviously other means for rigidl connecting and separating the top. and ottom frame structure maybe provided.

The top face of the lower frame structure 11 beyond the supporting rods 20, and the lowerface of the lower flange 14 of the upper frame structure 10, also beyond said supporting rods are formed with relatively deep peripheral grooves 22 therein. and the top and bottom edges of a rectangular or other shaped jacket or shell 23 are received therein. The assembly of the shell and upper and lower frame structures will take place simultaneously. The joint between the shell and the lower frame structure is preferably made oil tight by suitable means, as by peening the walls of the groove into forcible contact with the lower edge of the shell or by running a sealing medium in the groove. The joint between the upper edge of the shell and the upper frame structure may be made in a similar manner although I it is not important that the joint'be oil tight therefore it may be suflicient, and even ref erable, as regards subsequent disassem ling of theswitch structure, merely loosely to receive the the upper edge of the shell in its groove,

Other satisfactory means of uniting the shell with the upper and lower frame structures may be rovided; and in Fig. 7 the shell is secured the screws or rivets-24.

The shell and'the upper and lower frame Top flanges 13 and bottom' to the frame structure by structures form a casing in which other switch components are contained and when the cover-is applied to the upper frame structure the switch components are completely enclosed. The casing also forms the spill receptacle for the switch; 3

Said shell 23 is provided with a plurality of perforations or openin s 25 at its upper of the cell. This arrangement admits of removing the entire switch from the cell, after having first disconnected the switch leads andoperating mechanism, for inspection or for other purposes.

The switch casing is closed by the cover 29 which is secured to the upper flange 13 of the upper frame structure by the bolts 30; and the cover may be'removed by removing said bolts. Said cover preferably is concave in form for strength and has a plurality of ribs 31 extending transversely of it additionally to strengthen it. Openings 32 are formed in the cover, between said ribs,

and the stationary switch-members 33 arev secured therein and depend below the cover in the usual manner. The upper terminal portions 33 of said switch members are formed for detachable connection with the switch leads 34, as is usual with this type of switch.

The switch operating mechanism 35 is entirely contained within the switch casing and supported by the upper switch frame; and the movable switch member 36 pivotally depends therefrom. A member 37 of the operating mechanism extends through an opening 38 in the cover and is detachably connected, at 37, with a member 39 of the elecf tricallycontrolled mechanism 40 as is also customary practice.

The oil receptacle 41 of the usual rectangular shape is contained entirely within the switchcasing and is removably and resiliently supported therein. The top of the oil receptacle is loosely received within the opening 16 in the lower flange of the upper frame structure 10. The oil receptacle is, sufliciently smaller than said opening 16 to providea suitable clearance space 42 be-v tween it and the frame structure whereby to provide a vent passage of suitable dimenalone from the expansion space above the oil in the receptacle to the chamber or compartment containing the body of the oil rece ab y of substantially uniform width throug out its peripheral extent.

The bottom of the oil receptacle is freely received within the well or recess 18 and is preferably normally supported a substantial distance from the bottom to admit of the free vertical movement of the oil receptacle when it yields upon circuit interruption. A suitable clearance passage 43 is also preferably provided between' the side wall of the oil receptacle and the wall of the recess to admit of the escape of oil that may have accumulated in the recess when the receptacle is moved downward.

There are a number of suitable methods by which the oil receptacle may be resiliently supported within the casing. The method illustrated in Figs. 1, 2 and 3 may be preferable for some purposes. In these figures, the oil receptacle is provided with the rods 44 which are secured to the upper edges and adjacent the corners thereof and extend upwardly through openings 45 in the switch cover 30. The upper ends of said rods are threaded and coil springs encircle the rods and bear upon the cover. Nuts 46 are adjustably threaded upon said rods and engage the upper ends of said springs whereby the oil receptacle is yieldingly supported through said springs from the cover. The cover and oil receptacle may be separated by removing said nuts 46.

In Figs. 7 and 8 the oil receptacle is supported from the switch casing independent of the cover. -Lugs 47 are formed in the lower flange 14 of the upper frame structure, adjacent the receptacle opening 16 therein. Recesses 48 are formed in said lugs and compression springs 49 are received therein. Supporting members 50 are se cured to the side walls of the oil receptacle at the top and downwardly-extended portions. 51 thereof spaced from the side wall are received within said recesses 48 and bear upon the upper ends of said springs 49 whereby the oil receptacle is yieldingly supported; Removal of the oil receptacle is accomplished'simply by lifting it out of the caslng.

In the modification illustrated in Fig. 9 the oil receptacle rests upon the plate or platform 52 movably disposed within the well 18 of the lower frame structure; and the platform rests upon the compression springs 53 supported from the bottom of the well.

Upon the occurrence of abnormal gaseous pressure conditionsin the expansion chamber l2 above the oil in the oil receptacle, as due to circuit interruption, the oil receptacle will be moved downwardlyjagainst its supporting ptacle; and the oil receptacle is prefer-' so supported that said vent passa e is springs thereby to increase the volume of said expansion chamber and also to absorb energy developed.

Air and other vapor, and liquid oil thrown from the receptacle will be discharged through the vent passage 42 into the lower portion of the switch casing, or the spill chamber 54, thereby relieving the pressure in the upper expansion chamber. The hot. gases and vapor will be cooled by the cold' ing through the vent openings 25. It is to be noted that said vent openings are above the end of the apron 17 so that the vapor and oil is discharged directly downward away from the openings; and due to the relatively great volume of the spill chamber .practically all of the oil will condense and collect at the bottom and only uncondensable gas and vapor will escape from the casing; and the discharge of gas and vapor will not be violent.

The construction above set. forth provides an exceedingly large expansion chamber, as compared with the present cell type of switch and admits of a marked increase in the interrupting capacity of the switch.

Oil whlch may escape from the oil receptacle through a hole burned through the side wall of the receptacle due to an are coming in contact with the side wall will collect in the. spill receptacle and will not escape into the station as has been the case in that type of switch having no enclosing receptacle for the oil receptacle.

, The term oil is herein used generically to denote any suitable insulating or are quenching medium.

I claim:

1. An. electric vswitch comprising a covered casing, an open-top, fluid-containing receptacle received within said casing, and switchmembers carried by and extended through said easing into said receptacle.

2. An electric switch comprising a movable covered casing, an open-top, fluid-containing receptacle removably received within said casing, and switch-members carried by th casing having their inner ends disposed within said receptacle and their outer ends disposed externally of the casing.

3. An electric switch comprising a covered casing, a fluid receptacle yieldingly recei ed within said casing, and switch-members carried by the casing having their inner ends disposed within said receptacle and their outer ends disposed externally of the casing.

t. An electric switch comprising a movable covered casing, a. fluid receptacle removably and yieldingly received within said casing, and switch-members carried by the casing having their inner ends disposed within said receptacle'and their outer ends disposed externally ofthe casing.

5. An electricswitch comprising a casing, a fluid receptacle disposed within said casing, switch operating mechanism disposed Within said casing, a. movable switch-member associated with said mechanism depending into said receptacle, a removable cover for the casing and stationary switch members carried by said cover also immersed in the oil in said oil receptacle.

6. An electric switch having the combination of an enclosing casing, a fluid receptacle disposed within the casing, and means c0n-. necting said casing and Oil receptacle yieldingly.

7 An electric switclyhaving the c'ombination of an enclosing casing, a fluid receptacle disposed within the casing, means including springs connecting said casing and receptacle yieldingly to support the latter in position, a removable cover for said casing, and switch-members carried by said cover depending into said receptacle.

8. An electric switch having the-combination of an enclosing casing, a removable cover for said casing having apertures therein, a fluid receptacle disposed within saidcasing having extensions extended through the aperturesin said cover, and springs engaging said extensions and cover whereby yieldingly to support said oil receptacle in. position.

9. An electric switch having the combination of an enclosing casing, a removable cover for said casing having apertures therein, a fluid receptacle disposed within said casing having extensions extended through the apertures in said cover, and springs removably engaging said extensions and cover whereby yieldingly to support said oil receptacle removably in position.

10. An electric switch having a fluid receptacle and components enclosing an upper gas expansion chamber above the fluid in the receptacle and a second gas expansion chamber surrounding said receptacle disposed below and in communication with said upper expansion chamber and also with the atmos-- phere.

11. An electric switch having an oil receptacle and components enclosing a gas expansion chamber above the oil in the receptacle, a second gas expansion chamber peripherally disposed about said oil receptacle having vent openings at the upper'portion thereof communicating to the atmosphere, and means to direct gas and oil vapor from said first chamber into said second chamber below said vent openings.

12. An electric switch comprising a casing having an upper frame structure formed with a receptacle-receiving opening therein,

a lower frame structure having a receptaclereceiving recess therein,,means rigidly connecting and separating said frame structures one above the other with the opening and recess therein in alignment, and an oil reception movably supported in said opening and recess.

13. An electric switch comprising a casing having an upper frame structure formed with a receptacle-receiving opening therein, a lower frame structure having a receptaclereceiving recess therein, means rigidly connecting and separating said frame structures one above the other with the opening and recess therein in alignment, anoil receptacle.

yieldingly supported in said opening and recess, and an enclosing shell surrounding said oil receptacle extended between and secured to peripheral portions of said frame structure.

14. An electric switch comprising an enclosing casing, an oil receptacle disposed withinsaid casing and peripherally spaced therefromwhereby to provide an expansion chamber between it and the side wall of the casing, said casing extended above the top of said oil receptacle to form a gas expancasing and receptacle in positionincluding means to support said fluid receptacle yieldingly.

17. An electric switch having a casing. a fluid receptacle received within said casing and means independently to support said casing and receptacle in position including resilient means to support said fluld receptacle yieldingly. h

18. An electric switch having a casing, a fluid receptacle received within said casing and means independently to support said casing and receptacle in position, including means removably to support said fluid receptacle yieldingly.

19. An electricswitch comprising a fixed switch frame, stationary and movable switch members supported thereby, a' receptacle adapted to contain a fluid in which said switch frame switch members are immersed having means resiliently to support it fromsaid frame and a fixed outer receptacle contalning said fluid receptacle.

20. An electric switch having, as a unitary structure, the combination of a switch frame, a-fluid receptacle yieldingly disposed therebelow, supporting means disposed beneath said receptacle, and connectinghnd separating members connecting said supporting means and switch frame.

21. An electric switch having, as a unitary structure, the combination of a switch frame, a fluid receptacle yieldingly disposed therebelow, a carriage disposed beneath said receptacle, and. connect ing and separating members connecting said carriage and switch frame. r

22. .An electric switch having, as a unitary structure, the combination of a switch frame, a fluid receptacle yieldingly disposed there below, a carriage disposed beneath said receptacle havin a well in which the bottom of the receptac e is disposed and guided, and connecting and separating members connecting said carriage and switch frame.

23. An electric switch having, as a unitary structure, the combination of a switch frame,

a fluid receptacle yieldingly disposed therebelow, a casing enclosing said receptacle and connecting and separating members extended between the bottom of said casing and said switch frame and disposed within said casing.

24. An electric switch having, as a unitary structure, the combination of a switch frame, a fluid receptacle yieldingly disposed beneath said frame, said frame having downwardly extended extensions by which it is s uplportcd in fixed position above the receptac e.

25. An electric switch having, as a unitary strncture, the combination of a switch frame, a fluid receptacle yieldingly disposed beneath said frame, said frame having ClOWIlwardly-extended extensions by which it is supported in fixed'position above the re ceptacle and a casing enclosing said yieldingly disposed receptacle ;and said exten' sions.

26. An electric switch having, as a unitary structure, the combination of a switch frame,

a fluid receptacle yieldingly disposed therebelow, and a platform disposed beneath said receptacle, and connecting and separating members connecting said platform and comprising vertical rods threaded in said, frame and fixed to said carriage.

27 An electric switch having, as a unitary structure, the combination of awswitch frame,

a fluid receptacle yieldin ly disposed below said frame, and a plat orm disposed be-' neath said frame and receptacle arranged to support said frame in fixed position.

28. An electric switch having the combiv nation of a switch frame, a fluid receptacle disposed therebeneath, a platform disposed below said receptacle, means connecting and separating said platform and switch frame,

and a jacket secured to said platform and extended upwardly toward said switch frame and enclosing said receptacle.

29. An electric switch having the combi nation of a switch frame, a fluid receptacle disposed thcrebeneath, a platform disposed below said receptacle, means connecting and separating said platform and switch frame, and a jacket secured in fluid tight relation to said platform extended upwardly toward said switch frame and enclosing saidreceptacle. v

30. An electric switch having the combinationv of a switch frame, a fluid receptacle disposedtherebeneath, a platform disposed below said receptacle, means connecting and separating said platform and switch frame, and a jacket secured in fluid tight relation to said platform extended upwardly toward said switch frame" and enclosing said connecting and separating means and said receptacle I 3]. .An electric switch having the combinationof a switch frame, a fluid receptacle disposed therebeneath, 'a platform disposed below said receptacle, means connecting and separating said platform and switch frame,

and a jacket secured in fluid tight relation with and to said platform extended upwardly toward and received in a peripheral groove in said switch frame and enclosing said receptacle.

32. An electric switch including a switch frame, stationary and movable switch members and operating mechanism carried thereby, a wheeled carriage and supporting means removably connecting said frame with and in spaced relation to said carriage, and an oil receptacle receivedwithin said supporting means.

33. An electric switch including aswitch frame, stationary and movable switch members and operating mechanism carried thereby, a truck and means connecting said switch frame and truck arranged to support. said frame in position above said truck, said cpnnecting means also arranged to support said switch frame and its components when said truck is removed.

In testimony whereof, I have 'signed my name to this specification.

GEORGE A. BURN'HAM. 

